CVE
Eclipse AAS Model for Java server-side request forgery in XML validator
Only affects Eclipse AAS4J versions before 3.0.1 when an application validates untrusted XML with XmlSchemaValidator.validateSchema() or AASXValidator.validateSchema(). Fixed in 3.0.1.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 3.0.1
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 3.0.1.
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 25/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Eclipse AAS4J (Eclipse AAS Model for Java) before 3.0.1 has an XML external entity flaw in its schema validator, which is also reached through its AASX package validator. A remote attacker with no login can submit a crafted AAS XML document or AASX package to read local files on the host, send their contents to an external server, or make the validating process send outbound requests.
Read the original description
In Eclipse AAS4J before 3.0.1, XmlSchemaValidator.validateSchema() (and AASXValidator.validateSchema(), which calls it) validates untrusted XML with a default JAXP Validator that resolves external DTDs and external entities. An attacker who supplies a crafted AAS XML document or AASX package can read local files from the host, send their contents out-of-band to an attacker-controlled server, and make the validating process send arbitrary outbound requests (SSRF). Validation still returns no errors.
Details:
- Vulnerable code:
dataformat-xml/src/main/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/xml/XmlSchemaValidator.java.schema.newValidator().validate(new StreamSource(...))runs withoutACCESS_EXTERNAL_DTD/ACCESS_EXTERNAL_SCHEMArestrictions and withoutdisallow-doctype-decl. - Second entry point:
dataformat-aasx/src/main/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/aasx/AASXValidator.java. The AAS XML part of an.aasxpackage is passed unchanged to the vulnerable validator. XmlDeserializer(Jackson/Woodstox) is not affected, because DTD support is disabled by default there.- Present since the initial import of the code base (commit
cc9da52). - Fix: harden the validator by setting
ACCESS_EXTERNAL_DTDandACCESS_EXTERNAL_SCHEMAto""and rejectingDOCTYPEdeclarations. The bundledAAS.xsddoes not need DTDs, so no functionality is lost.
Who should check
Teams running Eclipse AAS4J before 3.0.1 that validate AAS XML or AASX packages with XmlSchemaValidator or AASXValidator, including the aas4j-dataformat-xml and aas4j-dataformat-aasx artifacts.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed, reachable over the network without a login · Unknown: Advisories don't say whether default setups are affected
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.7/10CVSS 7.7
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
- Would score about 30 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 3.0.1.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-127031 (In Eclipse AAS4J before 3.0.1, `XmlSchemaValidator.validateSchema()` (and `AASXValidator.validateSchema()`, which calls it) validates…), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-127031 (entry last updated 2026-11-13):
Affected:
- Eclipse Foundation Eclipse AAS Model for Java (Eclipse AAS4J): fixed in 3.0.1
Fixed versions: 3.0.1.
Conditions (all must be true for the bug to be hit):
- Eclipse AAS4J versions before 3.0.1 (all released versions from 1.0.0-milestone-01 up to and including 3.0.0). (source: https://gitlab.eclipse.org/security/cve-assignment/-/work_items/571)
- Application calls XmlSchemaValidator.validateSchema() directly, or AASXValidator.validateSchema() on an AASX package's AAS XML part, on untrusted input. (source: https://gitlab.eclipse.org/security/cve-assignment/-/work_items/571)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-127031 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-127031 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/eclipse-aas4j/aas4j
- https://github.com/eclipse-aas4j/aas4j/blob/main/dataformat-xml/src/main/java/org/eclipse/digitaltwin/aas4j/v3/dataformat/xml/XmlSchemaValidator.java
- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/571
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-127031
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-127031"}.Timeline
- CVE published
- Record last updated
- First seen by cve.now
Affected versions
- Eclipse Foundation Eclipse AAS Model for Java (Eclipse AAS4J)
fixed in 3.0.1
Evidence 5
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Link
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-127031
Is CVE-2026-127031 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The XML schema validator can be tricked into reading local files from the host and sending their contents to an attacker-controlled server. It can also make the validating process send arbitrary outbound requests, a server-side request forgery (SSRF).Source: gitlab.eclipse.org
Which versions are affected by CVE-2026-127031?
Eclipse AAS Model for Java (Eclipse AAS4J): before 3.0.1.Source: cve.now feed data
Am I affected, and how do I check?
Eclipse AAS4J releases from 1.0.0-milestone-01 up to and including 3.0.0 are affected. The risky setup is an application that calls XmlSchemaValidator.validateSchema() directly, or AASXValidator.validateSchema() on an AASX package's AAS XML part, with untrusted input. To check a project, look at the eclipse aas4j version in its dependency file and see whether it is 3.0.0 or earlier.Source: gitlab.eclipse.org
How do I fix CVE-2026-127031?
Upgrade Eclipse AAS4J to version 3.0.1, which is the fixed release.Source: gitlab.eclipse.org